Back in August, we reported on the construction of New York State’s first passive house, and since then, the green building standard has been gaining speed in New York City — especially in Brooklyn. The borough’s fourth passive house construction, a four-story historic Park Slope brownstone, is on track to be the nation’s first townhouse retrofit to meet passive house standards. The renovation began in September 2009 after homeowner Justin Stewart wanted to see how close he could get his new residence to zero energy consumption – read on for a look inside!

The Brooklyn-based design-build firm Prospect Architecture both designed the renovation and managed the construction. The passive house standards target insulation issues and airtightness from the basement up to protect the house from outside temperatures changes. Stewart’s brownstone also had to meet landmark requirements, which meant purchasing expensive triple-glaze custom windows that match the originals while reducing air leakage.

Two energy-recovery ventilators provide a constant supply of fresh air and filter pollution from outside air to help keep indoor temperatures comfortable year-round. The renovation also included the installation of two EcoSmart ventless fireplaces, a solar hot water, new wood floors, two new kitchens, and remodeled bathrooms, plus extensive restoration of the interior woodwork. The Passive House Institute U.S. will visit Stewart’s home this month to test the building for certification.